


His Son

by candlelight_smiles



Category: Shadowhunters (TV), The Shadowhunter Chronicles - All Media Types
Genre: Alternate Universe - Canon Divergence, Angst and Hurt/Comfort, Asmodeus is One Pissed Off Demon, Dysfunctional Family, Episode: s02e12 You Are Not Your Own, Family Feels, Good Parent Asmodeus (Shadowhunter Chronicles), Hurt Magnus Bane, Other Additional Tags to Be Added, Protective Parents
Language: English
Status: In-Progress
Published: 2021-02-25
Updated: 2021-03-13
Packaged: 2021-03-15 16:01:24
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 6
Words: 9,409
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29686428
Author URL: https://archiveofourown.org/users/candlelight_smiles/pseuds/candlelight_smiles
Summary: Asmodeus did not go to the plane where his son resided often. Mostly because of the whole banishing thing. Despite the inconvenience, Asmodeus could not help but feel pride at how strong his boy's spellwork had become. It prevented him from coming to Earth unless he was summoned, which was a rare occurrence. Thankfully for him, rare didn't mean it never happened. There always was a fool who wanted to summon a Greater Demon.When he discovers some filthy Nephilim is traipsing around in his son's body, Asmodeus ispissed.
Relationships: Asmodeus & Magnus Bane, Magnus Bane/Alec Lightwood
Comments: 54
Kudos: 163





	1. Chapter 1

Asmodeus was summoned to a courtyard in Sicily by a warlock that was barely out of her fifties. He had to give her points for just having the stones to summon him even if it was a very foolish endeavor. 

Making a deal with a demon, and a Greater Demon at that, required more experience and power than she possessed. If the pentagram broke before the demon agreed to the deal, then the deal was essentially void. The only pentagram Asmodeus had not broken out of was his son’s, and that was more of a familial politeness than from being unable to do so. 

Speaking of his son, it had been ages since he last saw him. Since the boy had banished him to Edom, actually. Which had been somewhat irritating. Demons thrived on chaos, and there was no better place to sew that than Earth. Demons loved sewing chaos on Earth. 

But despite the inconvenience caused from being banished from a plane of existence, Asmodeus could not help but feel pride at how strong his boy’s spellwork had become. It prevented him from coming to Earth unless he was summoned, which was a rare occurrence. Thankfully for him, rare didn’t mean it never happened. There always was a fool who wanted to summon a Greater Demon. 

Asmodeus had just been thinking the other day how nice it would be to speak with him again. It would be good to catch up with his son, see how he was doing. Maybe he was dating again or had a child. 

Warlocks couldn’t have children of their own, but Magnus did seem the type to adopt. He had always been rather… _compassionate._ An odd trait for a demon to have. Asmodeus could play at compassion, mimic it quite well at times, but he didn’t possess the qualities necessary to be genuinely kind like his son was. 

He did love Magnus, though. 

He could be civilized and not kill anyone while he was here. That ought to put him in his boy’s good books. Earn back his trust a bit, so he might summon him himself next time for a nice chat. Yes, Asmodeus liked the sound of that. 

With that plan in mind, he tracked down Magnus’s magical signature. It was in New York. Not at all a hassle for a demon like him to get to. All it took was a portal, and he was there. Asmodeus stood on the balcony of the apartment he felt his son in, a smile tilting his lips. 

He opened his mouth to announce his presence when he caught a glimpse of Magnus through the open doors. His smile fell, and the words faded from his tongue. Unbridled fury replaced his joy, blood boiling under his skin. 

It looked like Asmodeus might have to abandon his plan for the moment. 

What a pity. 

Valentine growled in frustration and hurled another random jar of herbs at the wall just to watch it shatter. He stamped his foot on the carpet, grinding his teeth to the point his jaw ached. He hated this. He hated everything about this. 

Damn Azazel and its impossible request. How was he supposed to get the Mortal Cup wearing a stupid warlock’s skin? Every demon blooded intruder that tried to enter was killed on sight. It just was not possible for him to fulfill what the demon wanted. 

The only thing he could think of was to switch himself back with Magnus Bane, so he would at least not be polluted with the warlock’s demonic blood. But a perusal of his library had turned up with nothing. How could he have no solutions to this problem? He was the High Warlock! Surely he had dealt with something like this before. 

Knowing his luck though, the knowledge was probably just in the warlock’s _mind,_ which was locked away in the Institute with his real body. 

“Stupid, disgusting, _filthy_ _warlock_. Why can’t you have anything _useful_ in here?” Valentine hissed under his breath. 

“Have care how you speak about my boy,” a voice growled. 

The hair on the back of his neck prickled, and Valentine whipped his head around. There was a man standing on the balcony, leaning against the doorframe that led inside the apartment. Valentine blinked. There was a reddish haze around the male shaped thing on the warlock’s balcony that Azazel had also had. 

“You’re a demon,” Valentine said. 

“Greater Demon,” it amended. “The filthy warlock you speak of is royalty.”

The demon stepped into the apartment. 

“So you’re a Prince of Hell,” Valentine said. “Which one are you?” 

He took a step back for each one that it took toward him. He had none of his weapons here, and he wasn’t a goddamn warlock. He had little to no control over any of Magnus Bane’s magic. He wasn’t in the mood to get choked by another Prince of Hell today. 

“Asmodeus,” it supplied. 

“What do you want?” Valentine asked, keeping his voice clipped and terse. 

“I wished to be able to converse with my son, but I am afraid to say that simply won’t be possible. You see, a fool stole his body,” Asmodeus said. 

The demon sounded quite calm, but the way that a decent sized patch of the sky outside went dark behind him betrayed his anger. His eyes were the same as his spawn’s, golden and slitted like a cat’s. 

“I didn’t _steal_ it,” Valentine retorted. 

“Didn’t you?” The lights flickered ominously overhead, and the door to the balcony swung shut of its own accord. “Because I see the soul of a Nephilim where my beautiful boy’s should be,” Asmodeus said. “Tell me where he is. Now.” 

Valentine scoffed. He was getting really tired of Greater Demons ordering him around. He was Valentine fucking Morgenstern, for the Angel’s sake. 

“I don’t negotiate with _demons,_ ” Valentine spat, echoing his earlier words to Azazel. 

Its head tilted, long hair brushing gently over its shoulder. It let out a soft tsk. 

“That is unfortunate…” Asmodeus said. “For _you._ ” 

Before Valentine could blink, it was across the room, standing right in front of him. Its hands darted out and clamped down over Valentine’s face, covering his eyes, mouth, and nose. Valentine’s gasp was muffled, and he tried to jerk away to no avail. The demon’s grip was like steel. 

Asmodeus pressed the pads of its thumbs to his forehead. Valentine felt it enter his mind like a wrecking ball, callous and uncaring of the memories that it shredded to nothing to find what it wanted. The Clave’s agony rune paled in comparison to this mental anguish. 

He couldn’t stop screaming. 

Valentine barely registered when it finally stopped. He couldn’t think at all. His brain hurt too much. The only thing that left his raw throat was a weak groan. Valentine flinched when it lowered its hands to his throat, expecting more pain. 

He was surprised to have the discomfort of his throat muscles taken away instead. Valentine blinked stupidly up at the demon, uncomprehending. Gold swam in his vision. 

“Huh?” Valentine managed. 

The demon lightly squeezed his throat, drawing an involuntary squeak from his mouth. 

“Do not mistake my actions for kindness, Nephilim. The only reason you are still breathing is because you are within my son’s body. I suspect he shall want it back in mint condition. The very _second_ you are not-” Nails that were previously not sharp were suddenly razors, pressing into his neck. It was applying just enough pressure for him to feel the deadly points against his throat, not enough to break skin. “You’re _mine,_ ” it breathed into his ear. 

The demon scraped its claws gently up to Valentine’s cheek. Its grin was drenched in malice, pure rage barely contained behind its distinctly inhuman eyes. It finally let go of his throat with its other hand. Valentine collapsed to the floor without anything holding him up. 

His world faded in and out in shades of red and black.

Asmodeus tapped the foot closest to him with the tip of his shoe, and the Nephilim whimpered pitifully. Well, at least he was not dead. It would be slightly harder to switch them back if one of the hosts was dead. Not impossible. Just slightly more of a pain to accomplish. 

He would not have been surprised if the Nephilim were brain dead from the rough treatment he had put his mind under. He had been far harsher than strictly necessary extracting information. That happened when Asmodeus got angry. 

Asmodeus kind of hoped that the Nephilim was not a total gibbering lunatic. They were more fun to torture when they were cognizant. Well, it didn’t particularly matter. If his mind was too broken, Asmodeus could always steal his soul and take it to Edom. Souls were a lot more resilient than human minds. 

He scooped Magnus’s body off the floor, smoothing a hand over his face to take away the headache that had to be blooming from cracking his head against the ground. He meant what he said. He wanted Magnus to come back to a nice and healthy body. 

Asmodeus hummed under his breath as he set the body on the couch and bound it with his own essence. Glowing ropes of red energy lashed him to the seat. Just in case the Nephilim came to his senses and tried to escape. One could never be too careful. 

He nodded to himself and opened another portal. Time to fetch his son. 


	2. Chapter 2

Azazel had known it would be risky, messing with his brother’s son. But he had intended to switch them back as soon as he got what he wanted, and he knew how little Magnus liked to tell his father about what happened in his life. It had been extremely unlikely Asmodeus would ever find out what he had done. 

Magnus had not given a single offering at his brother’s altar in over three centuries. A detail that irked Asmodeus more than he would care to admit. 

To anyone else besides the Fallen, it would not have been noticeable. Asmodeus had had millennia to perfect his stoic mask. But Azazel had known him when they were both mere angels, serving under and praising their Father. Asmodeus missed that insolent child of his deeply. 

Azazel could not understand _why._ He had had many children himself in the early days, and he personally did not care whether they lived or died. He had not even spoken to most of them. Azazel would have mocked his brother for such a weakness, this persistent and irritatingly parental love of his, but the truth was that Asmodeus was all the more vicious when it came to defending his ‘precious boy’. 

Once, when Magnus was just a little gutter rat fresh from the streets, Asmodeus had nearly gotten into a war with the Morningstar himself. Simply because Lucifer had _insulted_ his child in an offhanded comment. 

The would be war ended after a particularly violent scuffle between the two Greater Demons, which, upon the conclusion of said scuffle, had Lucifer being thrown into the deepest pit in Edom and buried alive under boiling sulfur. It took Lucifer thirty years to crawl back out. 

After that, the rest of the Fallen sort of got the hint to stay away from Magnus Bane. The kid was just a lot more trouble than he was worth. 

“Your father is such a _possessive bastard,_ ” Azazel muttered. 

He roughly pinched the boy’s cheek between his fingers and gave it a shake. Valentine didn’t make so much as a sound, staring blankly at him through Magnus’s dark eyes. His brother’s binding magic sizzled up and smacked Azazel’s hand. The skin burned off his glamour, peeling all the way down to the scarred rough skin of his demonic form. He hissed in pain and jerked back. 

“I hate you both,” Azazel said. 

There was a knock at the front door. He could smell the angel blood drifting off the Lightwood boy like a rancid perfume. The purity of it disgusted him. Azazel bit back a growl. 

“Magnus, you there?” 

Well, it was not as though Azazel had anything else going on right now. His only way to the Mortal Cup was currently a drooling mess. He might as well kill a pesky Shadowhunter to let off some steam before hiding from his no doubt furious brother. 

Azazel left Valentine and walked toward the door to unlock it. The Nephilim looked appropriately shocked when he saw him standing in the doorway instead of his boyfriend and even more so when he grabbed him and threw him into the apartment. Azazel had not counted on him being such a quick draw however. 

He had his bow out and fired before he even got close to landing on the ground. The arrow all but materialized in Azazel’s chest, puncturing directly below his sternum, with enough momentum to shatter his corporeal form instantly. 

_Shit,_ was all he had time to think before he was sucked back to Duduael. 

Azazel jerked his limbs in his chains, and his mouth fell open, eyes flashing tar black. The ground trembled with his rage filled roar. Lesser demons skittered away from him, chittering in fear. 

The bright lights flipped on again, and the squealing sound drilled into his skull. Magnus curled in on himself and winced, hands clamped down over his ears. In a way, it was less painful than the agony rune. It distracted him from the traumatic memories that had been dug up if only for a little while. 

That didn’t mean Magnus enjoyed this treatment. 

He couldn’t handle much more of this.

Any of this. 

All this torture. 

He felt like he was going insane. 

The noise finally stopped, and the lights switched back to a normal level. Magnus cautiously peeked up from his knees. The Inquisitor was standing on the other side of the glass, staring at him with disdain. 

“I put in a request for your execution with the Clave. You should be dead before sunrise,” Imogen told him. 

“No, no _please,_ ” Magnus begged for the umpteenth time. “I’m not Valentine! You have to believe me. Please, please don’t. You can’t.” 

The woman merely sneered at him and turned to leave. 

“ **_How dare you._ **” 

The loud and sudden rumble, more like thunder than a voice, startled Magnus. His hands flew up to his ears, wary of another barrage of noise. His eyes widened as an invisible force gripped Imogen by the throat and slammed her against the far wall so hard her head bounced off with a loud crack of skull on concrete. 

Okay… that definitely wasn’t another Clave interrogation tactic. Smoke spilled from the shadows like oil, surging toward the Inquisitor. 

“ **_You think you can kill_ ** **_my_ ** **_son? No._ **” 

She started to slide further up the wall, all but touching the ceiling. Imogen clawed in vain at the force restricting her breath, lungs no doubt burning from lack of oxygen. The cloud of smoke morphed into a tall man in all black. 

One that Magnus recognized all too well, even after all these years. 

Silver thorns circled the top of his head like a crown, and burning gold glared out of his eye sockets, looking directly at her. His hand was curled into a fist, red tendrils dancing over his skin. 

Magnus stared at his father, torn between confusion, fear, and a strange sort of relief. He couldn’t be here. How was he here? _Why_ was he here? 

“ **_Act on your desire, and I kill_ ** **_you_ ** **_,_ ** ” Asmodeus snarled. His lips tilted in a cruel, humorless smile. His voice lowered, turning sugary sweet, almost sickeningly so. “Is that simple enough for you to understand, Inquisitor? Or do you require a _demonstration?_ ” 

He twisted his other hand. The Inquisitor choked out a cough that sounded quite painful, and blood splattered across her hands. Asmodeus loosened his grip on her throat just enough so she could draw in a breath. 

“Speak,” he commanded. 

“I don’t know who your son is,” Imogen rasped. 

“Wrong answer,” Asmodeus said. 

His hand began to close up again, and her eyes bugged out. Her skin was starting to turn purple. Magnus staggered over to the glass and pounded his fist. 

“Father! Stop!” he pleaded. “Stop it!” 

His father’s head turned toward him. The handsome glamour was flickering, and Magnus could see his real demonic face, fading in and out just beneath the surface. Valentine’s eyes could not pick up the energy exuding from him, but he was sure that it had to be rolling around him in thick waves at this point. He looked absolutely enraged. 

“ _Please stop,_ ” Magnus insisted. 

Asmodeus’s glamour solidified. The flames in his eyes dampened considerably, menacing expression softening. His hand opened, and the Inquisitor toppled to the ground like a limp doll. Her eyes were shut, but the shallow rise and fall of her chest confirmed she was still alive. Asmodeus drifted over to the glass, brows furrowing. His hand rested over the clear surface. 

“My boy.” The thick sheet that comprised the glass wall melted and wavered under his palm, and he stepped inside. “What have they done to you?” Asmodeus murmured. 

He sounded… sad. Magnus had never heard him sound sad before. It was weird. In fact, he had been fairly sure that sadness, like love, was not something that demons could feel. Then again, his father had always been a good actor. 

Magnus barely held back a flinch when Asmodeus swept him into a tight hug, crooning concerned little endearments in Bahasa. The hug felt… kind of nice, but he half expected his father to squeeze him to death. After a few awkward seconds of not having his spine snapped or his ribs crushed, he chanced speaking. 

“Father?” Magnus said. 

“Yes?” Asmodeus replied. 

He leaned back to hold Magnus at arm’s length, giving him his full attention. There were a thousand questions on his tongue. 

“How did you find me?” was what Magnus settled on. 

“You needed me, so I came,” Asmodeus said. “How could I not? My child was scared and in pain. What father would I be if I ignored you in this state?” 

That didn’t really answer his question. 

“I meant like this. In this body,” Magnus clarified. 

“Bodies are merely decorative wrapping, son. I would recognize that bright soul of yours anywhere,” Asmodeus said. 

He clasped Magnus’s hands between his and smiled. Magnus absently noted that Valentine’s hands were larger than his father’s glamoured ones, and his fingers could not close over most of their surface area like with his own. 

“Why aren’t the guards coming?” His father had been quite loud earlier when he was throttling Inquisitor Herondale. “Did you kill them?” Magnus asked. 

“You always think the worst of me,” Asmodeus sighed, feigning offense. 

“You are the worst person I know,” Magnus said. 

That made the demon preen a little. 

“Thank you,” Asmodeus replied. 

“Did you kill my friends or not?” Magnus asked. 

His father’s face darkened. 

“Your _friends?_ They are _not_ your friends. Friends should not lock you up and torture you.” 

Magnus felt his heart squeeze. He grit his teeth and ignored it. 

“ _Father,_ ” Magnus said sternly. “Answer me.” 

His father looked like he wanted to roll his eyes. 

“No, unfortunately, I did _not_ kill them. Let’s just say the Institute has a new infestation of roaches,” Asmodeus replied. 

Magnus blinked. He hadn’t expected that. 

“You… turned them all to roaches?” he said. 

The Greater Demon nodded. 

“That form suits them much better,” Asmodeus commented. “Now come. Let’s get you back where you belong.” 

Not this again. 

“I’m not going to Edom,” Magnus told him. 

His father tsked, shaking his head. 

“You misunderstand me,” Asmodeus said. He waved a hand, and a portal opened up. “Come along. You’ll see what I mean.” 

Magnus made a face at that. He did appreciate the thought of not being tortured, but he wasn’t sure he should trust his father. Of course, in this body, he had no magic, so it was not as though he could prevent Asmodeus from dragging him into the portal. 

And refusing to go with him would probably anger him. Magnus didn’t want to deal with him like that, not right now. He was just so… exhausted. Mentally and physically… emotionally, too. If worse came to worst, he could always try to escape later. 

He hesitantly lowered his head in a nod. His father looked pleased and gave his hands a gentle squeeze that was likely meant to be reassuring. Magnus did not feel reassured. They stepped through the portal together.


	3. Chapter 3

**Notes for the Chapter:**

> Sorry this one is a little shorter, guys. I know I'm gonna be busy with school stuff for the next couple days, and I just wanted to keep the ball rolling. Crank out an update before I get swamped. 
> 
> I'll try to make sure the next couple chapters are longer, though. : )

When they portalled into Magnus’s loft, and he saw _yet another Nephilim,_ Asmodeus really wanted to toss him out the window. Especially when the boy got out his weapon and pointed it at them. 

However, Magnus insisted that he could handle this and started talking to him. After a few minutes of fruitless arguing and ‘Valentine this’ and ‘Valentine that’, Asmodeus had had enough. 

He lifted his hand and clicked his fingers together. The Nephilim froze for a split second, reddish gold dust puffing up over him. The bow and quiver clattered to the floor uselessly next to a tiny brown cockroach. 

Asmodeus felt his son’s eyes on him, so he turned his head. Magnus was looking at him like he had just murdered a million puppies and dumped their mutilated corpses in his lap. Asmodeus cocked a brow in askance. 

“What?” he inquired. 

His son’s face closed off, staring at the insect as his lips thinned, and when he finally spoke, he sounded a little strangled. 

“I had that handled,” Magnus said. 

“Eh,” Asmodeus responded, unconvinced. 

It had not seemed that way from his point of view. In fact, the Nephilim’s disbelief in what Magnus had been telling him had only seemed to cause his son more pain. Pain was indeed the path to enlightenment, but that did not mean Asmodeus wanted to see his child suffer. 

“I can’t believe you turned my boyfriend into a cockroach,” Magnus said. 

“You’re dating a _Shadowhunter?_ ” Asmodeus asked. 

He waved a hand at the cockroach that was rather determinedly darting toward Valentine’s feet. It crawled over the neat black shoe and perched itself on his toes, glaring up at them with its beady black eyes. 

Asmodeus had thought his boy had better taste than that. He swallowed his displeasure at that new factoid and kept his features neutral. They could discuss his dating life at a later time. There were more important things to deal with. 

Magnus ignored his query. 

“Turn him back,” he said, pointing at the cockroach for emphasis. 

“Of course.” Relief filled his son’s eyes. “As soon as we get you situated in your true body, I will return him to his previous state,” Asmodeus concluded. 

“You’re going to switch us back,” Magnus said. As though he had just realized it for the first time. Asmodeus nodded helpfully. His son seemed baffled. “Why?” 

It was Asmodeus’s turn to be confused. He felt himself start to frown. 

“‘Why’? Why wouldn’t I?” Asmodeus replied. 

“What are you getting out of this?” Magnus asked. “What do you _want_ from me?” 

“All I want is a chance to be your father again. In the centuries since you banished me, not a day has gone by that I haven’t felt the pain of losing you.” He touched his son’s shoulder. “I know you built your own life here among these mortals, but you are still my child. Please allow me to care for you,” Asmodeus said. 

Magnus was silent for several moments, staring intently down at a patch of carpet by his feet. He slowly pushed Asmodeus’s hand off his shoulder. Asmodeus was prepared for yet another rejection. 

“Fine,” Magnus finally muttered. 

“Fine?” Asmodeus repeated. 

His black heart felt half a shade lighter. 

“I’m pretty sure I’m going to regret this, but yeah. Fine,” Magnus said. 

Asmodeus grinned and held out his hand to his son. Magnus placed his hand in his, and Asmodeus curled his fingers around it, giving it a warm squeeze. He guided him over to the couch, gesturing for him to sit down next to Valentine. 

“Why is he like that?” Magnus asked. 

He waved a hand at the still bound man. 

“I was… angry,” Asmodeus said. The lights flickered briefly. He took a deep breath to calm himself before continuing. “He violated you.” 

Asmodeus pressed a finger to the magical bonds, and they vanished. Valentine stirred, if only to open his eyes and groan. 

“Loathe as I am to admit to this, it was not actually his fault,” Magnus told him. “Valentine Morgenstern is guilty of more atrocities than there are grains of sand in the world, but he didn’t do this.” 

“Who did?” Asmodeus asked. 

“Azazel. He switched us with the _unum ad unum_ sp-” Magnus cut himself off, jumping slightly in his seat when his coffee table suddenly caught on fire. “Um… Father?” 

Asmodeus absently waved his hand to put out the fire. 

“I’m going to kill your uncle,” he decided with an air of calmness that did not suit his current mood. 

“...okay,” Magnus said. 

“I will hunt down every last child of his first, cut them to pieces, and shove them down his throat.” The flames in his eyes burned brighter. “Then, I will tear off his wings-” 

His son held up a hand. 

“ _Please_ don’t tell me how you’re going to do it,” Magnus said. “I don’t want details.” 

“You’re right. Back to the matter at hand,” Asmodeus conceded. 

He placed a hand on Magnus and Valentine’s foreheads. A Chthonian phrase spilled from his lips, power surging under his fingertips. The men’s eyes dissolved into the same shade of black, more akin to the void of space than demonic tar. Their skin glowed white under his palms. 

When Asmodeus took his hands away, the colors faded. Both men were momentarily unconscious from the ordeal. He felt satisfied nonetheless that he could see his son’s soul in his son’s body. 

Things were just that much righter in the world. 

He kissed the top of Magnus’s head and smoothed down his dark hair. Asmodeus pulled him into his arms, so he could take him to a bed to rest. The poor child had had a trying day. 

Maybe more than a day. He was unsure how much time had passed since Azazel (that pathetic bitch was going to _wish_ God had never brought him into existence when he was done with him) had switched them. 

Asmodeus had actually forgotten that the Nephilim was there (the boyfriend one) until he almost stepped on it. It must have gotten dislodged from Magnus’s shoe when he picked him up. Oops. It scurried after him, following him all the way to the bedroom. 

“You’re persistent, I’ll give you that,” Asmodeus said. 

He laid his son down on the bed, arranging his head on the pillow with the utmost care. There. Much better. 

Asmodeus plucked the Shadowhunter off the ground and walked out of the room with him. He supposed he did have to turn him back now. That didn’t mean he couldn’t put the fear of, well, _Asmodeus_ into him, too. 

The little idiot hadn’t realized Magnus was not himself, and that was simply unacceptable. 

Asmodeus tossed Valentine in a portal to Edom for his asmodei to keep warm until his return. Whether or not the man was at fault for stealing his son’s body, he was still going to torture him. Probably a lot, if he was being honest. 

Asmodeus loved torturing people even when he wasn’t incredibly angry on his son’s behalf. 

The Greater Demon plopped himself down on the couch, kicking his heels up on the ashy coffee table. He’d have to find his boy a new one. Or magic the singed bits better if he were particularly attached to it. Asmodeus blew on the cockroach and tossed it into the air. A human boy landed on the floor. Well, half human. Disoriented hazel eyes blinked up at him. Asmodeus fixed him with his most sinister look, piling on an extra dose of menace just for effect. 

“Hello, Alexander.” Feline fangs glinted in the low lighting, golden eyes glowing with Hellish fire. “You and I need to have a little chat.”


	4. Chapter 4

“Hello, Alexander. You and I need to have a little chat.”

It had been a _very_ long morning. The severe emotional whiplash of the last half hour alone was enough to make his brain to mouth filter go offline for a bit. 

“You’re Magnus’s father?” Alec said, sounding perhaps a little more shocked by that information than he needed to be. 

Logically, Alec knew that all warlocks had a demon parent. That was kind of how they were born in the first place. He had just never expected to meet Magnus’s. For one, demons basically never stuck around to help raise the child. They merely got the mother pregnant and left. Demons were not exactly known for being fans of children. 

The demon in question gave him a slow and sarcastic clap. 

“Congratulations. Despite your other faults, you do not appear to be deaf,” he replied, tone drier than sandpaper. 

“Why did Magnus banish you?” Alec asked. 

He must have struck a nerve with that. 

The air in the room grew thinner. Darker, heavier. The feline slits contracted further, barely faint lines against fiery gold. A muscle in the demon’s jaw twitched. 

As he tilted his head forward, the silver thorns seemed to turn the color of fresh blood as shadows hit them, deep crimson glinting off the unnatural spiky arrangement woven over the demon’s long hair. His voice was soft but austere, steeled with an edge of utter finality. 

“That is none of your business, Nephilim.” The word ‘Nephilim’ was spoken like literal filth, all but spat from his mouth. “And even if it were, do you think I need _your_ permission to see my son?” the demon said. “ _You?_ You could not recognize your own lover.” His upper lip curled back in a slight snarl, flashing sharp incisors. “ _Pathetic._ ” 

In hindsight, there had been plenty of signs, but he had been worried that it was all some sordid trick of Valentine’s somehow. That didn’t make it better, though. Magnus had been hurt, tortured even, and Alec hadn’t helped him. He hadn’t believed him. 

Another sharp stab of shame and guilt twisted in his heart like a jagged knife. 

“I know. I should have… I’m… I’m sorry,” Alec found himself saying. 

He knew how inadequate that sounded. He _knew_ it. 

Magnus’s father knew it, too. 

“Apologies are cheap. That sad little face will probably convince my son. Might take him a while, but he’ll forgive you eventually.” 

Slender fingers tapped against a black clad knee. Golden eyes bored into his very soul. 

“I don’t forgive, and I never forget. So do not think this instance of lenience will let you off the hook. I intend to keep a close eye on you. I know what your kind thinks of the Downworld. Less than the dirt beneath your angelic heels. What was it that drew you to my son? Was it the taboo? Forbidden fruit does taste the sweetest. Or was it his power? Did you covet it for yourself?” the demon demanded. 

“What? No. I don’t care about that kind of thing. I care about _him,_ ” Alec said. 

The demon raised a brow, clearly unconvinced by his words. 

“Magnus loves with all he has. He always wants to believe the best of people, and if you turn out to not be whatever you’ve led him to believe you are… if you harm him… well. I am very old and very creative. Your darkest nightmares cannot compare to what I shall do to you. There is no place on this godforsaken planet that you can hide from me. No spell, no rune that can shield you from me. I will find you. And I will destroy you,” he relayed with deadly calm. 

“I understand.” Alec swallowed around the lump in his throat. “If that happens, you’re welcome to do whatever you want to me,” he said. 

“I will hold you to that,” the demon replied. 

His head snapped up suddenly, shoulder length hair bouncing slightly with the movement. Gold melted into dark brown, slitted pupils turning short and round. One second the demon was seated in front of him, and the next Alec was left staring at an empty couch. 

Alec blinked, mildly thrown off by the abrupt change. He quickly shook off his surprise and pushed up to his feet. A short glance around revealed where the demon had gone. The hem of a sleek pant leg and the heel of a black shoe disappeared into the hallway. 

He hesitated for a moment before walking after him. Alec followed him all the way to Magnus’s room. From the doorway, he could see Magnus stirring on the bed, moving to sit up. His back was to the door. The demon turned his head, locking eyes with Alec. 

The gentle, worried expression he had been watching Magnus with immediately hardened to stone. He did not say a word, but everything about his body language screamed ‘fuck off’. The door swung shut in Alec’s face without so much as a twitch of the demon’s fingers. He heard the lock click in place. 

Magnus woke up alone. He heard the door pull shut somewhere behind him. Magnus turned his head toward the noise. His father stepped closer to him, walking over to the other side of the bed to stand next to him. 

“Fa-ther?” Magnus said. 

The word came out strange and stilted in his surprise. 

“I’m here, my son,” Asmodeus murmured. 

A warm hand rested against his back, rubbing in soothing circles. Magnus leaned into the touch for a few seconds before he caught himself. He pushed his father’s hand away and glanced up at him. 

“You’re still here,” Magnus said. 

A little hum of confirmation answered him. 

“It is my understanding that parenting is a full time occupation,” Asmodeus replied. “How do you feel?” 

“I’m okay,” Magnus said. 

His father gave him _the look._

“Do not lie to me. I can taste your anguish,” Asmodeus reminded him. 

“I know you mean that literally, but it sounds weird when you say it like that. And kinda creepy,” Magnus said. 

“You’re deflecting,” Asmodeus responded. 

Magnus sighed. 

“I feel terrible, alright?” he said tiredly. 

“Is there anything I can do to ease your suffering?” Asmodeus asked. 

“Not really.” He shook his head. “I just need to rest. Thanks for switching me back,” Magnus muttered. 

His father’s expression brightened slightly. 

“Of course,” Asmodeus replied. 

Speaking of switching things back… 

“Father, where’s Alexander?” Magnus asked. 

“He is still here. I believe he is in the hallway,” Asmodeus supplied. 

“Is he-” Magnus asked. 

“Yes, he has two legs again,” Asmodeus said. He patted Magnus’s shoulder with a small smile. “A promise is a promise.” 

Magnus kneaded at his eyes. Smudged eyeliner came off on the back of his hand. He was so tired. He knew he should take a shower. Eat. Something. There were so many things he should probably do. 

But he could barely muster the energy to move. 

“Can you…” He met his father’s eyes again. “If you still want to make me feel better, you could turn the other Shadowhunters back,” Magnus said. “I’ll just get called in to fix that anyway.” 

“That would make you feel better?” Asmodeus asked. 

Not really, but it would lighten his workload. 

“A little,” Magnus said. 

“Very well,” Asmodeus replied. “I will return soon. Please don’t do anything overly strenuous in my absence.” 

“So no marathon then?” Magnus said. 

His father frowned. 

“No, you can’t go to Greece,” Asmodeus told him. 

“What? No, not the town. You know, it’s like a forty kilometer race,” Magnus said. The Greater Demon stared at him blankly. “Never mind. It doesn’t matter. I was joking.” 

“Oh,” Asmodeus replied. “I see.” 

His father portalled off, leaving Magnus alone. 

Magnus didn’t really want to be alone. 

He wasn’t sure how long it took him to finally move from the bed. It could have been minutes or hours. He unlocked the door and stepped into the hallway, a fresh robe draped over his arm. His towel was already in the bathroom. 

Magnus saw Alec in the living area out of the corner of his eye, cleaning up bits of glass from the carpet. Alec noticed him and stood up. 

“Magnus, I-” Magnus looked at him. “I’m so sorry. I pushed you and I yelled at you and I didn’t believe you. I let you get _tortured-_ ” 

Alec’s breath hitched, and his eyes were bright with unshed tears. 

“Alexander,” Magnus said quietly. 

He didn’t want to talk about it right now. About any of it. 

Obviously, it was yet another thing he’d need to deal with. He and Alec had to talk about what happened at some point. But not right now. Later. 

“I’m so sorry, Magnus. I’ll - I can leave if you want me to,” Alec rushed out. “I understand. I’m probably the last person you want to see right now.” 

“ _Alexander,_ ” Magnus repeated, this time with a little more force. Alec fell silent. “You don’t have to leave. Just… wait. Okay?” 

Alec nodded. 

“Yeah. Okay,” he said. 

“I’m going to take a shower,” Magnus told him. 

His boyfriend nodded mutely. Magnus continued toward the bathroom and pulled the door shut behind himself. He stared at his face in the mirror.


	5. Chapter 5

Asmodeus went to visit the Madame Inquisitor first. 

Her attempt to attack him was rather unsuccessful. Pitiful, really. With a flick of his finger, he had her subdued, bound to his will. He kept her from speaking with another spell. She would likely only aggravate his rage further. 

“Did you know Magnus is my favorite child? I know, I know. Parents are not meant to have favorites, but like my Father before me, I just cannot help myself.” The heels of his shoes clicked softly against the cement floor as he paced toward her. “He is my sole heir, and even if he does not want my throne or to rule by my side, I do care for him. I must repay you for the kindness you treated my son with,” Asmodeus said. 

Her eyes widened slightly, confusion and fear flickering over her features, as he made her lift her hand. Asmodeus turned his own hand back and forth, watching as she mimicked his movements. 

“An eye for an eye and all that,” he told her. 

Asmodeus mimed reaching for an invisible stele on his hip, and the Inquisitor helplessly imitated him. Her stele was clenched between her fingers. He pushed up his left sleeve and guided her hand, drawing the agony rune in smooth strokes. Asmodeus had seen it branded over the forearm of the body Magnus had been in. While he had not been present at such a time, he was more than certain they must have used it on him. 

With another wave of his ‘stele’, he activated it. 

The woman  _ screamed. _ Her skin burned red under the self inflicted rune, raw and inflamed. Asmodeus made her activate it again and again and again. He gave her no breaks between. The very second she stopped screaming, he swept his hand in the same motion to cause her to reactivate the agony rune. 

He would have made her do it until she dropped dead from the stress it was putting her body under, but he  _ had _ promised his son he would do something else for him while he was here. Waiting long enough for the wretched Nephilim to finally die would probably take too long. 

Magnus was no longer a child, but after an event that had seemingly traumatized him, he did not feel comfortable leaving him alone for long periods of time. 

(That Shadowhunter boy was with him, technically, but Asmodeus did not want to count him. Only time would tell if he was actually a good companion for his son.) 

So Asmodeus only did it until her voice was so hoarse from screaming it was scarcely more than a whisper. He released her from his hold, and her stele dropped out of her fingers like it had scorched her, clattering to the floor at her feet. The Inquisitor slumped against the wall for support, knees buckling under her weight. Each breath sounded rather laborious. 

Asmodeus patted her cheek just to watch her flinch. 

“If I catch you so much as looking at my son funny, I will peel off your skin and devour your soul,” he said calmly. 

Asmodeus turned and walked out of the room. 

He brought his hands together as he went down the hallway, glowing red manifesting in a whirring ball in the space between the crooked fingers, and he spread his arms in a smooth motion. Demonic magic washed over the inside of the Institute, rendering his previous transformative spell useless. 

Asmodeus opened up another portal to his left and made his exit. 

Magnus took a lot longer in the shower than he usually did. Almost forty five minutes longer than he usually did. Alec didn’t comment on it. He didn’t say anything at all until Magnus sat down on the other end of the couch, dressed in a pair of silk pajama pants and one of his robes, which was cinched tightly shut. 

His face was bare of the messy makeup that Valentine hadn’t bothered to take off from the night before, and the longer sections of his hair rested against his forehead and the tops of his ears, wet and limp. His nails looked pale without their black polish. 

It did sting more than a bit that Magnus could not even look at him. He knew he deserved that, though. 

“Magnus…” Alec started. “I am so sorry for everything you had to go through. What I…” His throat closed up. He had to swallow a few times before he could keep going. “I know I hurt you, too. And I am so sorry.” 

Magnus said nothing. 

“I think a part of me knew something was off, and I still didn’t realize… I didn’t believe you. I was so worried it was another one of Valentine’s tricks-” Alec said. 

“I know,” Magnus interjected. Those two syllables, soft though they were, were more effective than any yell. Alec stopped talking. “I understand, logically, why you did what you did. I don’t blame you for reacting like you did.” His eyes slipped shut, and a silent sigh huffed past his lips. “I just… the way you looked at me.” 

“Magnus.” The first tear slipped down his cheek. “I’m sorry,” Alec said. 

He could probably say that a thousand times, and it wouldn’t be good enough. Not after what had happened. 

“That agony rune… made me relive memories I’ve spent centuries trying to forget,” Magnus murmured. His voice wavered, just shy of cracking. 

“Please tell me how to fix this. Tell me what to do,” Alec pleaded. 

He got a tiny shake of the other man’s head in response. 

“You can’t fix this, Alexander. Not in a day, at least. We… I… need time,” Magnus said. 

Alec nodded. 

“Do you want me to sleep at the Institute tonight?” he asked. 

“No. I meant what I said earlier. I do need time and some space, but you do not have to leave,” Magnus said. 

“Okay,” Alec replied. 

They were silent for a while after that, both lost in their own thoughts. Neither moved to sit closer to the other. 

Magnus laughed suddenly. It wasn’t a happy laugh. Obviously. It was more… disbelieving and kind of sad. Alec started a little at the unexpected sound. He looked over at his boyfriend. 

“You know, I haven’t seen my father in three hundred years. I always thought he would kill me if he ever saw me again,” Magnus admitted. “We didn’t exactly part ways on good terms.” He stared at the far wall with a blank expression on his face. “He hugged me.” 

“He… hugged you,” Alec repeated. 

The way Magnus had said it made it seem significant. 

“Yeah… he  _ just… _ ” He made a frustrated gesture before dropping his hands back to his lap. “I don’t understand  _ why, _ ” Magnus sighed. 

“He seems…” Alec tried to find the right word. “protective of you,” he ventured. 

The warlock’s lips thinned a little. 

“He can be.” He finally looked at Alec. Worry flashed across his face. “He didn’t do anything else to you, did he? While I was unconscious, I mean,” Magnus said. 

“Oh, uh, no. He didn’t do anything to me. We just talked,” Alec explained. 

Brown eyes narrowed infinitesimally. 

“About?” Magnus prompted. 

“He told me if I ever hurt you, he’d hunt me down and destroy me,” Alec said. 

“That does sound like something he’d say,” Magnus muttered. 

“Is your father a Greater Demon? You don’t have to answer if you don’t want to. I was just wondering… normal demons can’t portal in and out of the Institute like that,” Alec said. 

His boyfriend was silent for a couple of moments. 

“He is. His name is Asmodeus,” Magnus told him. 

“Asmodeus?” Alec echoed. “Oh.” 

“Look, I’m sorry I never told you about him. I was… well, I was ashamed,” Magnus said. 

He continued to stare down at the ground. 

Alec wanted nothing more than to hug him. But it was too soon for that. Wasn’t it? He didn’t want to end up making Magnus uncomfortable than he already was. Hesitance kept him glued to his seat. 

“You don’t have to apologize. You did nothing wrong,” Alec insisted. 

It didn’t really matter who or what Magnus’s father was anyway. He loved  _ Magnus, _ not his father. And Magnus was perfect the way he was. 

Magnus’s cheek twitched ever so slightly. His gaze lifted from the ground. 

“I’m hungry,” Magnus said quietly. 

Alec opened his mouth to ask him what he wanted to eat. He was already halfway off the couch, ready to head to the kitchen. 

“Then it is a good thing I stopped for food on the way back,” a familiar voice chimed in. 

Alec blinked and watched as the Greater Demon walked toward them, holding a paper bag. He hadn’t even heard him portal in. Maybe he had teleported or whatever like that other time instead of portalling. 

Asmodeus reached into the bag and handed Magnus something wrapped in a napkin with a warm smile. 

“Here, son. For your strength,” he said. Magnus unfolded the napkin and gave the oversized pretzel a quizzical look. Asmodeus sat down next to him, setting the paper bag on the table. He ignored Alec entirely. “If you don’t like that kind of food, I can find you something else.” 

“It’s… fine,” Magnus told him. 

He took a small bite out of the pretzel. 

They all sat on the couch in awkward silence while Magnus ate. 


	6. Chapter 6

Alec’s phone rang, and he excused himself before going answer it in the other room. When he came back, he was wearing his serious Shadowhunter face. Standing rigid like a soldier as he informed them of the situation. 

“I’m sorry. I have to, uh, go. I have to report back to the Institute. Among other things, I need to explain what happened to Valentine and Azazel,” Alec said. His gaze flicked to Asmodeus. “I don’t suppose you would be willing to return Valentine to our custody?” 

“No,” Asmodeus replied. Magnus looked at his father. “What? I have to torture him.” 

“Valentine knows where the Mortal Cup is. The Clave wants to make sure that it doesn’t fall into the wrong hands,” Alec said. “That was the main reason they hadn’t approved of his execution yet.” 

“I do not care. He hurt my son. He has to suffer. If him escaping is your concern, I can assure you that no person of angelic blood has ever survived a trip to Edom. He isn’t about to become the first,” Asmodeus drawled. 

“...right.” Alec shifted on his feet. He looked back at Magnus. His face remained neutral, but Magnus knew him well enough to know that he was uncomfortable. “I’ll be back as soon as I can. Are you sure you’ll be okay?” Alec asked. 

Magnus forced a small smile to his face. 

“Yeah. I’ll be fine,” he insisted. “Go.” 

Alec took a step toward Magnus before seeming to think better of it. He turned and walked toward the door. The sound of the front door closing was deafening in the otherwise silent apartment. 

Magnus dropped his head in his hands and sighed. 

“What’s wrong, son?” Asmodeus asked. There was a slight pause. “Is it the memories the agony rune brought up? I have dealt with that woman, but I am certain that does not make you feel better.” 

Did he even want to know what he meant by ‘dealt with’? Probably not. Magnus rubbed his temples and looked back at the Greater Demon. 

“It’s not that. Well, I mean, they are still bothering me. A lot. But that’s not why I’m…” 

He trailed off with a frown. Asmodeus patiently waited for him to continue. Magnus started again with another sigh. He wasn’t ready to talk about Alec with him, so he chose a topic that was also bothering him. 

“Look, Father. I know I said I would let you take care of me or whatever, but as the High Warlock, I cannot really allow you to remain in this dimension. It would be negligent on my part to let such a threat to my people be out and about,” Magnus explained. 

“I would not harm anyone under your jurisdiction,” Asmodeus said. “I may be a demon, but I am not unreasonable. I will only exact vengeance on those who hurt or try to hurt you, and I reserve the right to defend myself if need be.” 

“You say that now. What happens when you decide you want to sew some chaos? What’s to stop your thirst for darkness from unleashing on this world? I know how you get. Better than anyone,” Magnus responded. “I just… I can’t-” 

“Magnus. I swear to you that I will not cause them harm,” Asmodeus insisted. 

“Demons are not angels. They are not bound to their promises,” Magnus said. 

“But there are promises that even demons can be bound to,” Asmodeus countered. 

A dagger appeared in his right hand. He slashed the opposite palm open faster than Magnus could blink and dipped his index finger into the ichor that welled up. Black stained his tanned skin. 

“You can’t be serious,” Magnus said. “A _blood oath?_ ” 

Blood oaths were rarely ever used anymore, if only because of the fact that if the person who gave their blood to the keeper of their contract did not hold up their side of the bargain, they would suffer immense pain over an extended period of time as their body rotted from the inside out before eventually being killed. 

It was _dark magic,_ the kind that had been outlawed by the Elders of the Spiral Labyrinth ages ago. It was also exactly the kind of thing a demon would never, should never, agree to. Especially a Greater Demon. It was just considered a very unwise move. 

He grabbed his father’s wrist, halting his movements. Asmodeus looked back at him. The epitome of calmness. 

“You do not trust me to keep my word. This will ensure that you can believe me when I say that I am only here to be your father,” Asmodeus told him. 

A parchment appeared in the air in front of them, hovering in a shower of golden sparks. His father’s true name, the one only angels could pronounce correctly, was scorched into the bottom. There was a blank space beside it for the drop of blood required to seal the oath. Chthonic covered the rest of the page in neat lines. 

“You can read it first if you’d prefer,” Asmodeus offered. “But I do intend to sign it.” 

Magnus grabbed the parchment. His father’s magic tingled under his fingertips. The terms of the oath were quite simplistic, essentially repeating what he had said earlier in a more formal format. The rest of the writing was the standard cautions and warnings of the consequences for violating the agreement. 

The only condition that Magnus was obligated to follow was to allow Asmodeus to remain in this dimension to ‘protect and cherish’ him. Which was something that Magnus had already agreed to a few hours ago. His father had even listed him as the holder of the contract rather than the other way around. 

“Are you positive that you want to sign this? I wouldn’t ask this of you,” Magnus said. 

He was still his father. It was one thing to banish him to Edom. It was another to condemn him to a potentially horrid death for doing what Princes of Hell did. 

The dagger vanished from Asmodeus’s hand, and he reached over to pat Magnus’s knee. 

“I know.” He plucked the contract from his hand. “However, I would like you to be able to rest without worrying about me plotting to destroy the world or some such nonsense,” Asmodeus stated. His eyes rolled toward the ceiling for a brief moment. “I _do_ have self restraint.” 

A single drop of ichor hit the parchment, inciting a low sizzle. The scorch mark of his name turned a glistening red. Asmodeus handed the paper back to Magnus. The cut on his hand was gone. 

“I still would say this is too extreme of a gesture to show good faith, but then again, this is you we’re talking about,” Magnus said. 

He took the parchment from him and sent it to his safe. 

“Now that _that’s_ settled-” Magnus’s eyes widened as he was pulled into yet another hug. “I am so proud of you! _High Warlock._ I knew my son was destined for great things,” Asmodeus crooned. 

Magnus awkwardly lifted his arms and patted his father’s back. 

“You didn’t know I was the High Warlock?” he asked. 

The Greater Demon gave him one last squeeze before leaning back. 

“You must forgive me for being out of touch. It’s not like you write… or call… or perform the occasional blood sacrifice,” Asmodeus said. He touched his own chest with a small pout. “It wounds your fond parent’s heart.” 

“Considering the way we left things, I did not assume you would want to talk to me,” Magnus admitted. 

“If there ever was a person in this universe I would always want to talk to, it would be you,” Asmodeus said. “Silly boy.” He lightly pinched Magnus’s cheek, giving it a playful tweak. “You worry too much.” 

“Are you saying you weren’t angry with me?” Magnus asked. 

“Of course I was. But I missed you more,” Asmodeus said. “Did you truly think that I would stay angry with you for eternity?” 

“Well, you do hold grudges for obscenely long periods of time. I wouldn’t have been surprised if that were the case,” Magnus replied. “Like, that time with Lucifer. Have you forgiven _him_ yet?” 

His father’s face darkened. 

“He called you scrawny,” Asmodeus growled. 

It was almost comical how genuinely pissed off he was at the mere mention of that incident.

“I _was_ scrawny,” Magnus reminded him. 

“That wasn’t your fault. You hadn’t been eating well,” Asmodeus retorted. 

“Scrawny is not even close to the worst thing I’ve been called. And no-” Magnus said quickly as his father opened his mouth. “I will not tell you who insulted me. Most of them aren’t even alive anymore.” 

“Mm. Fine.” His hand suddenly tapped Magnus’s arm. Magnus blinked. “Oh! Would you like some bandrek?” Asmodeus asked. 

“Bandrek?” Magnus repeated. 

“It used to be your favorite. Do you still like it?” Asmodeus asked. 

“I… wouldn’t say it’s my favorite, but I mean, I guess I do,” Magnus said. He wasn’t even that thirsty, though. “But you don’t have to-” 

“Nonsense. Of course I do.” His father slipped off the couch. “You have been deprived of my cooking for far too long. I must remedy that,” he declared. 

“Um…” 

Magnus could only watch as the Greater Demon flounced off with all the determination of a general marching into battle. Well. Okay then. It looked like he would be having bandrek.


End file.
